Modeling of Monostatic Bottom Backscattering from Three-Dimensional Volume Inhomogeneities and Comparisons with Experimental Data.
Abstract
In this thesis, an attempt has been made to model monostatic backscattering from 3-D volume inhomogeneities in the sediment and to compare the results with ARSRP backscattering data obtained in a sediment pond on the western flank of the Mid-Atlantic Ridge. A scattering process cannot be modeled correctly without a proper account of the incident field. Several approximate propagation models have been evaluated against the exact solution. This study concludes that precautions need to be taken in modeling both the propagation effects and the scattering mechanisms associated with the bottom volume scattering process. A volume scattering model based on perturbation theory and the Born approximation is developed incorporating contributions from both sound speed and density fluctuations. With the propagation part handled accurately by OASES and random fluctuations generated effectively by a new scheme modified from the spectral method, the model is capable of simulating the monostatic backscattered field and time series due to 3-D volumetric sediment inhomogeneities. The model matches the ARSRP backscattering data very well, with the fluctuations of sound speed and density in two irregular sediment layers, identified from the data analysis, described by a power law type of power spectrum.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1997
- Accession Number
- ADA342953
Entities
People
- Dan Li
Organizations
- Woods Hole Oceanographic Institution